OBJECTIVE: To determine structural and functional changes in canine left ventricular myocardium resulting from chronic protein-calorie malnutrition. Any specific alterations elucidated would provide a rationale for aggressive clinical dietary therapy of nutritional disorders possibly contributing to cardiac function. METHODS: Chronic preparations of matched dogs with specific protein-calorie malnutrition would, as their controls, serve as the experimental subjects for acute experiments to assess left ventricular performance. Open chest experiments with preparation of an isovolumetric left ventricle model on cardiopulmonary bypass will enable determination of baseline indices of left ventricular contractility, including force-velocity and length-tension relationships. Standardized stress variables of subendocardial ischemia and acute coronary artery ligation will be applied to further separate the malnourished from the normal animals. Nutrient-rich intravenous solutions will be infused to determine the the hemodynamic effects of these agents under the circumstances described. Biochemical assays of myocardial stores of substrate and high energy phosphate substances will differentiate the two groups on metabolic bases, and histological examination of myocardium under routine light and electron microscopy will determine any structural effects induced by starvation. Any changes identified will have potential clinical application not only in the fields of clinical cardiology and parenteral nutrition, but will give a better understanding of potential cardiovascular complications of prolonged starvation.